In sensor apparatuses including a plurality of sensor elements, voltage values corresponding to the detection result of the amount of sensing by the respective sensor elements are outputted from a signal processing circuit, and further digital values corresponding to the voltage values are outputted from an A/D conversing circuit. Then, one- or two-dimensional distribution of the amount of sensing (e.g. light intensity, temperature, displacement) is obtained based on the digital values corresponding to the amount of sensing for the respective sensor elements. As an example of such a sensor apparatus, there can be cited an image pickup apparatus including a plurality of photodiodes that are arranged one or two-dimensionally (refer to Patent Document 1).    Patent Document 1: Japanese Patent Application Laid-Open No. H9-51476